# 42924: Per-connection protocol message rate exceeded

Identifier: `rate_limit_exceeded_protocol_message_rate_fatal`



A connection was terminated because the rate of inbound protocol messages from the connection exceeded its configured per-connection limit. Protocol messages include message publishes, presence updates, attach/detach requests, and other client-initiated actions on the connection.

## What you should do

The threshold is high (around 2000 protocol messages per second), well above what the official Ably SDKs send, so reaching it usually indicates a client that is not using an official SDK and is sending far more protocol messages than intended. Look for a loop or bug in that client, such as repeatedly attaching and detaching a channel or publishing in a tight loop. The connection can be re-established, but it will be closed again if the behavior continues.

## Why it happens

A connection may send only a limited number of protocol messages per second, around 2000, covering every client-initiated action on it and not just published messages. This is a safeguard against a misbehaving or runaway client. When a connection exceeds it, Ably closes the connection rather than rejecting individual messages.

## What you'll see

The connection is closed. The error is reported with code 42924 and HTTP status 429, with a message of the form `Connection terminated for abuse (inbound protocol message rate exceeded 2000/s)`.